L4 vs. L2

[matrixshaman]

The L2 is the brightest LED light I have bar none. I thought it was 120 Lumens on high mode. L4 I believe is 65 Lumens. The L2 has a lot of throw and good side spill too so nothing is going to surpise you from the side. But it is a bit longer. I wouldn't be without mine.

 

[matrixshaman]

BTW I measured output voltage from the L2 body with the head off - at the plus tab (not the battery) and it was 8.1 volts with standard 123's in it. So they are boosting the voltage before it gets to the head.

 

[Luna]

Ok not exactly L4 vs L2 but here it goes:

I just went out and got a L2 because I like my U2 so much.
Well, just a quick wall test of the two and I'm amazed at how much hotter the hot spot is on the u2. The kicker is that I'm running an old b65 so the U2 isn't geting the juice it would like to have. I must have won in the U2 luxlotto. Its whiter and brigter (and should be considering price difference)

I'll get back with more if anyone is interested

 

[KevinL]

The U2 has a tighter focus and would thus have a hotter spot. Try the ceiling bounce test - point the light up at a white ceiling and check out how well it lights up the surroundings from the reflected light. Compare the two lights this way.

My L4 vs U2 - the L4 is very close to it, but the U2 has a more intense spot due to its much deeper reflector.

 

[Luna]

Kevin, I did one step more. I did a ceiling bounce with a white door being photographed in manual mode. I used a p60 with new batteries for reference, the l2, u2 and u2 + l2.

I did a 25x25 point sample at a point in each picture to derive the rgb. I summed the components and applied a ratio to the known approximate output results.

P60=1*65lumens=65 lumens (hard math) (22 was the r+g+b score)

L2 rgb score =33 33/22 * 65 = 97.5 lumens
U2 rgb score =41 41/22 * 65 = 121 lumens
u2+l2 rgb score =78 78/22 * 65 = 230 lumens

Of course there is error in the ccd due to the bayer filter and other issues. The system isn't technically sound but is isn't a bad estimation assuming the p60=65lumens was a good calibration. So the simple test does help to back my claim of the difference between the two.

I'd imagine I can make it work better, including giving spectral results but it was more of a verification. I need to do the same without he B65 battery and also the 3x123 u2 which seems to give about a 20lumen increase (just a test not a long term burn because I like the u2 and I only have 3 levels vs 6 when doing this)

 

[KevinL]

Wow, NICE! Easy to do without a luxmeter and the milk carton test, too.

The 3x123 thing switches the U2 to something like direct-drive mode, for short term testing it should be ok (don't quote me on that although I am sure you know what you are doing). But that is a very nice U2 you have... /ubbthreads/images/graemlins/smile.gif

 

[Cornkid]

So the L2 has allot more output than the L4... ok..

-tom

 

[KevinL]

*hides his >100 lumen L4 while the L2 owners think they're where its at because the L2 is spec'ed higher* /ubbthreads/images/graemlins/rolleye11.gif

Realistically, ALL of them are subject to the Luxeon lottery. I keep saying (but some don't listen) that the L4 is only spec'ed at 65 lumens and realistically puts out a lot more than that. Mine positively STOMPS the P60 and puts up a heck of a fight with a P61 (120lu!) incandescent Surefire!

 

[rgc]

[ QUOTE ]
KevinL said:
*hides his >100 lumen L4 while the L2 owners think they're where its at because the L2 is spec'ed higher* /ubbthreads/images/graemlins/rolleye11.gif

Realistically, ALL of them are subject to the Luxeon lottery. I keep saying (but some don't listen) that the L4 is only spec'ed at 65 lumens and realistically puts out a lot more than that. Mine positively STOMPS the P60 and puts up a heck of a fight with a P61 (120lu!) incandescent Surefire!


[/ QUOTE ]


But were talking in overall light output not throw right? I am sorry if I am /ubbthreads/images/graemlins/dedhorse.gif I am just trying to learn as much as possible as fast as I can. Thus, your L4 will but out a wall of flood light that is greater then the P-60 and almost up to the P-61, however, it will not throw that hot spot of light farther than the P-60? Right?

rgc

 

[Luna]

Yes, output of light not throw. The neat thing with these high power LEDs are that they light up an area so well and smooth that you quickly learn that only minimal throw is needed.

I have projected light from the U2 and could detect it at considerable distance but you seldom need throw like we think we do. If the need arises, a Magcharger or $20 spotlight is hard to beat. The really big boys are novel and cool, but not practical for most people.